How To Change Mifare Card’s Key
Probably no body cares how to change Mifare Card’s key, but if you really want to learn this thing, please read.
My English is not well, because of this, i am going to tell you very clear.
Mifare Card’s has 64 Blocks, every 4 block has sector number. It means, Mifare Classic Cards has 16 Sectors.
Every Sector is protected by key. And these key stored on last block on the sector. Imagine just one sector. it has 3 normal blocks, and 1 trailer block.
In Mifare Card’s every block can store 16 Bytes. Including Trailer Sectors too.
First Six byte of Trailer sector is your Key A, and last 6 byte is your key B.
And what about other 4 Bytes? You can see in the image, red ones calls Access Bits. This is not just bytes, this controls all over your sector blocks. This tutorial subject is not Access Bits, we will talk it later.
Changing Mifare Card’s key means overwrite trailer sector with new bytes. You have to very carefull while you changing it. Because if you write wrong byte on the access bits, you should destroy your mifare card’s sector.
If you want to change your mifare card’s key, please use my program Mifare controller. You can download it from this link
